Electrode for Use in Measuring Dielectric Properties of Parts

ABSTRACT

A plate of substantially uniform thickness is formed from an electrically conductive material. The plate has a top surface defined to support a part to be measured. The plate has a bottom surface defined to be connected to a radiofrequency (RF) transmission rod such that RF power can be transmitted through the RF transmission rod to the plate. The plate is defined to have a number of holes cut vertically through the plate at a corresponding number of locations that underlie embedded conductive material items in the part to be measured when the part is positioned on the top surface of the plate.

CLAIM OF PRIORITY

This application claims priority under 35 U.S.C. 119(e) to each of thefollowing U.S. Provisional Patent Applications: 1) U.S. ProvisionalPatent Application No. 60/978,082, filed Oct. 5, 2007; 2) U.S.Provisional Patent Application No. 60/978,085, filed Oct. 5, 2007; 3)U.S. Provisional Patent Application No. 60/978,087, filed Oct. 5, 2007;and 4) U.S. Provisional Patent Application No. 60/978,089, filed Oct. 5,2007. Each of the above-identified provisional patent applications isincorporated herein by reference.

CROSS REFERENCE To RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No. ______(Attorney Docket No. LAM2P630A), filed on even date herewith, entitled“Apparatus for Measuring Dielectric Properties of Parts,” and U.S.patent application Ser. No. ______ (Attorney Docket No. LAM2P630C),filed on even date herewith, entitled “Methods for Measuring DielectricProperties of Parts,” and U.S. patent application Ser. No. ______(Attorney Docket No. LAM2P630D), filed on even date herewith, entitled“Methods for Characterizing Dielectric Properties of Parts.” Thedisclosure of each of the above-identified related applications isincorporated herein by reference.

BACKGROUND OF THE INVENTION

Semiconductor wafer (“wafer”) fabrication often includes exposing awafer to a plasma to allow the reactive constituents of the plasma tomodify the surface of the wafer. Such plasma processing of a wafer canbe performed in a plasma processing system in which a plasma isgenerated by transmitting radiofrequency (RF) power through a processinggas. The wafer characteristics resulting from the plasma processingoperation are dependent on the process conditions, including the plasmaconditions. Because the plasma conditions are closely tied to the RFpower transmission through the system, it is beneficial to have anaccurate knowledge of how the RF power is transmitted through the plasmaprocessing system. Knowledge of how the RF power is transmitted throughthe plasma processing system is also necessary to match one plasmaprocessing system to another, such that the plasma intensity in eachplasma processing system is substantially the same for a given powerinput. To this end, it is necessary to have an accurate knowledge of thedielectric properties of the plasma processing system parts throughwhich the RF power is transmitted.

Dielectric properties of interest can include the dielectric constant,and loss tangent of a particular part. One conventional technique formeasuring dielectric properties of a part includes manufacturing thepart with an attached sample coupon that can be removed and subjected todielectric property measurement. In this conventional technique thesample coupon can be of a small size relative to the actual part.Because the material composition in some parts, e.g., ceramic parts, issubject to spatial variation, there is a potential that the relativelysmall sample coupon may not provide a true representation of thematerial composition of the part as a whole. In this situation, thedielectric properties measured for the sample coupon may not be accuratewith regard to the actual part as a whole. Also, the dielectricproperties of a sample coupon for a given part, as reported by themanufacturer of the given part, may be measured at a frequency that isdifferent than the frequency of the RF power to which the given partwill be exposed during use. Because dielectric properties are frequencydependent, the reported dielectric properties of a given part may not beapplicable to the frequency of the RF power to which the given part isto be exposed, thereby requiring an extrapolation from the reporteddielectric properties of the given part and an assumption of thecorresponding extrapolation error.

In view of the foregoing, a solution is needed to enable measurement ofthe dielectric properties of actual full-sized parts to be used inplasma processing systems, and at the operating frequency of the RFpower to which the parts will be exposed during plasma processingoperations.

SUMMARY OF THE INVENTION

In one embodiment, an electrode for use in measuring dielectricproperties of a part is disclosed. The electrode includes a plate formedfrom an electrically conductive material. The plate has a top surfacedefined to support a part to be measured. The plate also has a bottomsurface defined to be connected to a radiofrequency (RF) transmissionrod, such that RF power can be transmitted through the RF transmissionrod to the plate. The plate is also defined to have a number of holescut vertically through the plate at a corresponding number of locationsthat underlie embedded conductive material items in the part to bemeasured, when the part is positioned on the top surface of the plate.

In another embodiment, a method is disclosed for defining an electrodefor use in measuring dielectric properties of a part. The methodincludes an operation for forming a plate of electrically conductivematerial to have an outer perimeter defined to substantially match anouter perimeter of a part to be measured. The part to be measured is adielectric part including a number of embedded conductive materialitems. The method also includes an operation for identifying a locationof each embedded conductive material item within the part. The methodfurther includes an operation for projecting the identified location ofeach embedded conductive material item within the part upon the plate,with the outer perimeters of the part and the plate substantiallyaligned. Additionally, an operation is performed to remove a portion ofthe plate at each embedded conductive material item location asprojected upon the plate.

In another embodiment, an electrode for use in measuring dielectricproperties of a ring-shaped part is disclosed. The ring-shaped partincludes a number of embedded conductive material itemscircumferentially disposed within the ring-shaped part. The electrodeincludes a plate formed from an electrically conductive material. Theplate includes a solid center region and a number of spokes extendingradially outward from the solid center region by an extent sufficient toenable support of the ring-shaped part on a top surface of each of thenumber of spokes. The number of spokes are defined and spaced about thesolid center region such that the number of spokes support thering-shaped part at locations between adjacent embedded conductivematerial items within the ring-shaped part.

Other aspects and advantages of the invention will become more apparentfrom the following detailed description, taken in conjunction with theaccompanying drawings, illustrating by way of example the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration showing an apparatus for measuring dielectricproperties of parts, in accordance with one embodiment of the presentinvention;

FIG. 2A is an illustration showing the chamber configured to enablevertical movement of the upper electrode, in accordance with oneembodiment of the present invention;

FIG. 2B is an illustration showing a top view of the chamber depictingthe relative placement of the three vertical positioning devices, inaccordance with one embodiment of the present invention;

FIG. 2C is an illustration showing the upper electrode lowered so as torest upon a top surface of a part, in accordance with one embodiment ofthe present invention;

FIG. 3A is an illustration showing a hinged version of the chamber, inaccordance with one embodiment of the present invention;

FIG. 3B is an illustration showing the hinged version of the chamber inan open state, in accordance with one embodiment of the presentinvention;

FIG. 4A is an illustration showing a closed version of the chamberhaving an access door, in accordance with another embodiment of thepresent invention;

FIG. 4B is an illustration showing the closed version of the chamberwith the access door removed, in accordance with another embodiment ofthe present invention;

FIG. 5A is an illustration showing an exemplary hot electrode configuredto accommodate a ring-shaped part including embedded conductivematerial, in accordance with one embodiment of the present invention;

FIG. 5B is a flowchart of a method for configuring the hot electrode foruse with a particular part, in accordance with one embodiment of thepresent invention;

FIG. 6 is an illustration depicting capacitances between the hotelectrode/RF rod and the grounded upper electrode/chamber when theexemplary part is disposed between the upper electrode and the hotelectrode, in accordance with one embodiment of the present invention;

FIG. 7 is an illustration depicting capacitances between the hotelectrode/RF rod and the grounded upper electrode/chamber when there isno part disposed between the upper electrode and the hot electrode, inaccordance with one embodiment of the present invention;

FIG. 8 is an illustration showing an exemplary curve of part capacitance(C_(part)) versus part dielectric constant (k_(part));

FIG. 9 is an illustration showing a flowchart of a method forcalibrating the relationship between the total capacitance (C_(total)_(—) _(without) _(—) _(part)) and the separation distance between theupper electrode and the hot electrode, in accordance with one embodimentof the present invention;

FIG. 10 is an illustration showing a method for determining acapacitance of a part (C_(part)), in accordance with one embodiment ofthe present invention;

FIG. 11 is an illustration showing a flowchart of a method fordetermining the dielectric constant of the part (k_(part)), inaccordance with one embodiment of the present invention;

FIG. 12 is an illustration showing a flowchart of a method fordetermining a loss tangent of a part, in accordance with one embodimentof the present invention;

FIG. 13 is an illustration showing an equivalent electrical circuitrepresentation of the apparatus with the part disposed between the upperelectrode and hot electrode, as depicted in FIG. 1, in accordance withone embodiment of the present invention; and

FIG. 14 is an illustration showing an exemplary fitting of Equation 5based on gain versus frequency data measured and recorded in a frequencysweep of operation.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Itwill be apparent, however, to one skilled in the art that the presentinvention may be practiced without some or all of these specificdetails. In other instances, well known process operations have not beendescribed in detail in order not to unnecessarily obscure the presentinvention.

FIG. 1 is an illustration showing an apparatus 100 for measuringdielectric properties of parts, in accordance with one embodiment of thepresent invention. In one embodiment, the parts to have their dielectricproperties measured are dielectric components of a plasma processingsystem. In this embodiment, the parts may correspond to components thatwill be exposed to RF power during the plasma processing operation, andthereby potentially influence the RF power transmission through theplasma processing system during the plasma processing operation.

The apparatus 100 includes a chamber 101 defined by a conductivematerial and electrically connected to a ground potential 141. In oneembodiment, the chamber 101 is defined by a conductive material ofsubstantially low electrical resistance such as copper. It should beunderstood, however, that in other embodiments, the chamber 101 can bedefined by other low electrical resistance conductive materials, such asaluminum among others. The apparatus 100 also includes an electricalcomponents housing 103 defined by a conductive material and electricallyconnected to a ground potential 139. In one embodiment, the electricalcomponents housing 103 is positioned below the chamber 101 and iselectrically connected to the chamber 101 so as to share a common groundpotential with the chamber 101.

The chamber 101 includes an interior cavity 102 defined to house anupper electrode 105 and a hot electrode 109. The upper electrode 105 isdisposed in an upper region of the interior cavity 102 over the hotelectrode 109. In one embodiment, the upper electrode 105 is defined asa plate of conductive material of low electrical resistance, such ascopper. In this embodiment, the upper electrode 105 plate is disposedhorizontally in a substantially level orientation within the interiorcavity 102. The thickness of the upper electrode 105 can vary so long asa rigidity of the upper electrode 105 is sufficient to maintain aplanarity of the upper electrode 105 across the interior cavity 102, andthe weight of the upper electrode 105 is not so great as to deform othercomponents that will bear the weight of the upper electrode 105. In theembodiment where the upper electrode 105 is defined as a copper plate,an exemplary upper electrode 105 thickness can vary from about 0.125inch to about 1 inch. In one particular embodiment, the upper electrode105 is defined as a copper plate of 0.25 inch thickness.

Also, a size of the upper electrode 105 is defined such that the upperelectrode 105 substantially covers a majority of the interior cavity 102horizontal cross-section area when the upper electrode 105 is positionedin a substantially level orientation within the interior cavity 102. Inone embodiment, the upper electrode 105 is sized such that the peripheryof the upper electrode 105 extends to within 1 inch to 3 inches of thechamber 101 when the upper electrode is centered within the interiorcavity 102 in a substantially horizontal, i.e., level, orientation.Also, in one embodiment, the upper electrode 105 is sized to extendbeyond a periphery of a part 111 to be measured by at least twice thevertical thickness of the part 111.

The upper electrode 105 is electrically connected to the chamber 101 byway of peripheral connections 107, thereby placing the upper electrode105 at the same ground potential as the chamber 101. The peripheralconnections 107 are defined to provide a substantially uniform groundingof the upper electrode 105 to the chamber 101 around the periphery ofthe upper electrode 105. In one embodiment, the peripheral connections107 are defined by flexible sheets of copper foil. In this embodiment, asolid sheet of flexible copper foil is defined to have a lengthsubstantially equivalent to the length of a side of the upper electrode105. In this embodiment, the flexible copper foil is electricallyconnected to the upper electrode along the entire length of the edge ofthe upper electrode 105. Also in this embodiment, the flexible copperfoil is electrically connected to the chamber 101 wall proximate to theentire length of the edge of the upper electrode 105. Thus, with anupper electrode 105 defined as a plate having four edges, four flexiblecopper foil strips are used to respectively connect the four edges ofthe upper electrode 105 to the chamber 101 wall.

The upper electrode 105 is also defined to be moved vertically withinthe chamber 101, as indicated by arrow 104. FIG. 2A is an illustrationshowing the chamber 101 configured to enable vertical movement of theupper electrode 105, in accordance with one embodiment of the presentinvention. In the embodiment of FIG. 2A, three vertical positioningdevices 207A-207C are provided at the top of the chamber 101. Each ofthe vertical position devices 207A-207C is defined to enable verticalposition control of a respective lifting member 203A-203C. Each liftingmember 203A-203C is defined to have a lifting rod with a disk attachedto its lower end. Three guide structures 201A-201C are connected to thetop surface of the upper electrode 105. Each guide structure 201A-201Cis defined to receive a respective lifting member 203A-203C. Morespecifically, each guide structure 201A-201C is defined to receive thedisk of the lifting member 203A-203C within an internal vertical guideregion. Each guide structure 201A-201C is also defined to include a tophaving an access sized to allow movement of the lifting rod therethroughwithout allowing movement of the disk of the lifting rod therethrough.Thus, each lifting member 203A-203C is defined to be moved in a verticaldirection 205A-205C by its respective vertical positioning device207A-207C.

The disk portion of each lifting member 203A-203C within each guidestructure 201A-201C is defined to engage the underside of the top of theguide structure 201A-201C so as to enable vertical positioning of theupper electrode 105 by way of the lifting members 203A-203C and guidestructures 201A-201C. Additionally, in one embodiment, each of thevertical positioning devices 207A-207C includes a vertical positionindicator that provides a measure of the vertical position of thelifting member 203A-203C, which in turn provides a measure of thevertical position of the upper electrode 105 in the vicinity of thelifting member 203A-203C. In one embodiment, the vertical positionindicators of the vertical positioning devices 207A-207C provide avertical position measurement to the nearest one-thousandth of an inch.

In addition to providing vertical elevation control of the upperelectrode 105, the three vertical positioning devices 207A-207C arepositioned on the top of the chamber 101 to also enable horizontalleveling control of the upper electrode 105 in all directions. FIG. 2Bis an illustration showing a top view of the chamber 101 depicting therelative placement of the three vertical positioning devices 207A-207C,in accordance with one embodiment of the present invention. An outline206 of the periphery of the upper electrode 105 is shown in FIG. 2B.Based on the placement of the three vertical positioning devices207A-207C, it should be appreciated that through independent control ofthe vertical positioning devices 207A-207C the horizontal leveling ofthe upper electrode 105 can be controlled.

As discussed in more detail below, during operation of the chamber 101the upper electrode 105 is lowered so as to rest upon a top surface of apart 111 to be measured. FIG. 2C is an illustration showing the upperelectrode 105 lowered so as to rest upon a top surface of a part 111, inaccordance with one embodiment of the present invention. To ensure thatthe upper electrode 105 is allowed to completely rest on top of the part111, the guide structures 201A-201C are defined to allow the liftingmembers 203A-203C to be lowered such that their disk members disengagefrom the top of the guide structures 201A-201C, thereby allowing theupper electrode 105 to rest freely on top of the part 111, as indicatedby the gaps 213A-213C between the lifting member 203A-203C disks and thetop of the guide structures 201A-201C. It should be appreciated that inthis embodiment the contact force between the upper electrode 105 andthe part 111 is defined by the weight of the upper electrode 105. Also,it should be understood that the horizontal area size of the groundedupper electrode 105 can remain the same regardless of the size of thepart 111 to be measured within the chamber 101.

While the vertical positioning devices 207A-207C and correspondinglifting members 203A-203B and guide structures 201A-201C represent oneembodiment for controlling the vertical elevation and horizontal levelof the upper electrode 105 within the chamber 101, it should beappreciated that variations of this embodiment can also be used forcontrolling the vertical elevation and horizontal level of the upperelectrode 105. For example, other embodiments can include additionalmechanics, such as gears and motors, not explicitly identified herein.Also, other embodiments can include electronic devices, such as motorsand sensors, not explicitly identified herein. Also, other embodimentscan include data acquisition and control interfaces to enable computercontrol and monitoring of the various vertical positioning devices207A-207C, and thereby of the upper electrode 105. Furthermore, itshould be appreciated that the peripheral connections 107 are defined toallow the upper electrode 105 to remain electrically connected to thechamber 101 wall as the vertical elevation and horizontal level of theupper electrode 105 is adjusted. In the embodiment where the peripheralconnections 107 are defined by sheets of flexible copper foil, thesheets of flexible copper foil are of sufficient size accommodate a fullrange of vertical movement of the upper electrode 105, within theinterior cavity 102 of the chamber 101.

With reference back to FIG. 1, the hot electrode 109 represents a lowerelectrode within the chamber 101 with respect to the upper electrode105. The hot electrode 109 is defined to support the part 111 to bemeasured. The hot electrode 109 is electrically connected to an RF rod113 through which RF power is conducted to the hot electrode 109 fromthe RF components within the electrical components housing 103. Both thehot electrode 109 and the RF rod 113 are defined to be electricallyisolated from the chamber 101. The hot electrode 109 is positionedwithin the interior cavity 102 to be far enough away from the groundedchamber 101 walls so as to avoid obscuring a capacitance of the part 111by the capacitance between the hot electrode 109 and the chamber 101. Inone embodiment, the hot electrode 109 is sized as small as possible, butnot smaller than the part size 111, so as to minimize the capacitancebetween the hot electrode 109 and the grounded chamber 101. Both the hotelectrode 109 and the RF rod 113 are defined by an electricallyconductive material of low electrical resistance, such as copper. Thehot electrode 109 is defined to have a vertical thickness sufficient toenable manufacture of the hot electrode 109 without distortion, and toenable support of the combined weight of the part 111 and upperelectrode 105 without distortion. In various embodiments, the hotelectrode 109 can be defined to have a vertical thickness within a rangeextending from about 0.125 inch to about 2 inches. In one embodiment,the hot electrode 109 is defined to have a vertical thickness, whendisposed within the chamber 101, of about 0.75 inch.

Also, in one embodiment, the hot electrode 109 can be configured toinclude alignment features to facilitate proper alignment of the part111 on the hot electrode 109. In one embodiment, proper alignment of thepart 111 on the hot electrode 109 is achieved when the part 111 issubstantially centered on the top surface of the hot electrode 109. Inone embodiment, such as that shown in FIG. 2A, the hot electrode 109 issupported by an electrically insulated support plate 209. In oneembodiment, a number of alignment pins are provided in the insulatedsupport plate 209 to enable accurate positioning and alignment of thepart 111 on the hot electrode 109. In various embodiments, the supportplate 209 can be defined by essentially any type of electricalinsulating material. In one embodiment, the support plate 209 is formedfrom a plastic material. Also, in one embodiment, such as that shown inFIG. 2A, the support plate 209 is further separated from the groundedchamber 101 by a electrically insulated stand 211. In one embodiment thestand 211 is defined by the same material as the support plate 209. Inone embodiment, the support plate 209 is defined as a solid plastic diskhaving an opening in the center through which the RF rod 113 can pass toconnect with the hot electrode 109. Also, in this embodiment, the stand211 is defined as a solid plastic right circular cylinder.

It should be appreciated that the hot electrode 109 is defined to be aninterchangeable component of the apparatus 100. Because the sizes of thevarious parts 111 to be measured will vary, it follows that the size ofthe hot electrode 109 will also vary. While the size of the hotelectrode 109 does not have to exactly match every part 111 to bemeasured, it is likely that the various parts 111 to be measured willvary sufficiently in size so as to necessitate use of different sizedhot electrodes 109. Also, the particular configuration andcharacteristics of a part 111 to be measured may require use of a hotelectrode 109 that is customized in size and shape. For example, if thepart 111 includes one or more embedded parts of conductive material, thehot electrode 109 may need to be defined to support the part 111 whilealso avoiding positioning of the hot electrode 109 beneath the embeddedconductive material within the part 111. For instance, if the hotelectrode 109 is positioned beneath the embedded conductive material,the embedded conductive material may provide for increased electricalcommunication between the hot electrode 109 and the upper electrode 105at the location of the embedded conductive material, which would not berepresentative of the part 111 as a whole. Because the part 111 to bemeasured can be of essentially any size and configuration and caninclude any arrangement of embedded conductive materials, it should beappreciated that the hot electrode 109 can be defined to haveessentially any size and configuration as necessary to accommodate theparticular characteristics of the part 111 to be measured.

FIG. 5A is an illustration showing an exemplary hot electrode 109Aconfigured to accommodate a ring-shaped part 111A including embeddedconductive material, in accordance with one embodiment of the presentinvention. The embedded conductive material is positioned within thering-shaped part 111A at locations 501. The hot electrode 109A isdefined to have a spoked-shape to allow the hot electrode 109A tosupport the part 111A while simultaneously avoiding placement of thepart's embedded conductive material above the hot electrode 109A.Specifically, the hot electrode 109A is defined to be absent atlocations 503 below the embedded conductive material locations 501. Itshould be appreciated that in the same manner that the exemplary hotelectrode 109A is specifically configured for the part 111A, other hotelectrodes 109 can be specifically configured for other parts 111.

FIG. 5B is a flowchart of a method for configuring the hot electrode 109for use with a particular part 111, in accordance with one embodiment ofthe present invention. The method includes an operation 510 for defininga plate of electrically conductive material, such as copper, to have anouter perimeter defined to substantially match an outer perimeter of thepart 111. In one embodiment, the part is a dielectric part including anumber of embedded conductive materials. The method also includes anoperation 512 for identifying the location of each embedded conductivematerial within the part 111. In an operation 514, the identifiedlocation of each embedded conductive material within the part isprojected upon the plate with the outer perimeters of the part and theplate substantially aligned. Then, in an operation 516, portions of theplate defining the hot electrode are removed at the locationscorresponding to the embedded conductive material locations projectedthereon. The size of each removed portion of the hot electrode plate issufficient to ensure that the hot electrode 109 is not located below theembedded conductive material within the part 111 when the outerperimeters of the part 111 and hot electrode plate 109 are aligned. Tothe extent possible, operation 516 is performed to ensure that the hotelectrode 109 remains a single, contiguous component.

With reference back to FIG. 1, the electrical components housing 103 isdefined to house a number of electrical components for conveying the RFpower to the RF rod 113 and enabling control of the resonance frequencyof the apparatus 100. As a grounded structure, the electrical componentshousing 103 is also defined to provide RF shielding. The electricalcomponents housing 103 includes a connector 129 to which an RF signalgenerator 125 is connected via a conductor 133. An RF voltmeter 127 isalso connected to the connector 129 via a conductor 135. The electricalcomponents housing 103 also includes a connector 131 to which the RFvoltmeter 127 is connected via a conductor 137. In one embodiment, theconnectors 129 and 131 are defined as BNC connectors.

The electrical components housing 103 also includes a conductor plate115 of low electrical resistance material, such as copper, through whichthe RF power is to be transmitted. The connector 129 is connectedthrough a capacitor 117 to the conductor plate 115 to enable the RFpower transmitted from the RF signal generator 125 to be conveyed to theconductor plate 115. The conductor plate 115 is also electricallyconnected to the connector 131 to enable electrical connection of the RFvoltmeter 127 to the conductor plate 115. The electrical componentshousing 103 further includes an inductor 119, a capacitor 121, and avariable capacitor 123, each of which is electrically connected betweenthe conductor plate 115 and the grounded chamber 101 bottom. In oneembodiment, multiple capacitors can be electrically connected betweenthe conductor plate 115 and the grounded chamber 101 bottom to providean equivalent of the single capacitor 121, as depicted in FIG. 1.

In one embodiment, the capacitor 121 (or its multiple capacitorequivalent) is used to support the conductor plate 115 in a position soas to be electrically separated from the grounded electrical componentshousing 103, thereby avoiding a short between the conductor plate 115and the electrical components housing 103. In another embodiment,electrically insulating support brackets can be used to support theconductor plate 115 off of the electrical components housing 103.Additionally, the RF rod 113 is electrically connected to the conductorplate 115 to enable transmission of the RF power from the conductorplate 115 to the hot electrode 109. The variable capacitor 123 can beadjusted to set the resonance frequency of the apparatus 100. Forexample the variable capacitor 123 can be set so that the resonancefrequency of the apparatus 100 is substantially equivalent to theoperational frequency of the RF power to be used in the plasma processto which the part 111 is to be exposed.

The chamber 101 can be configured in a number of ways with regard toproviding access for placement of the part 111 on the hot electrode 109and removal of the part 111 from the hot electrode 109. FIG. 3A is anillustration showing a hinged version of the chamber 101, in accordancewith one embodiment of the present invention. In the hinged version, thechamber 101 is defined by an upper chamber portion 101A and a lowerchamber portion 101B. A hinge 303 is provided to enable opening of theupper chamber portion 101A with respect to the lower chamber portion101B. FIG. 3B is an illustration showing the hinged version of thechamber in an open state, in accordance with one embodiment of thepresent invention. In the open state, the part 111 can be easily placedon the hot electrode 109 and retrieved from the hot electrode 109. Also,in the open state, the hot electrode 109 can be accessed forreplacement. Also, the hinged version of the chamber utilizes an RFgasket 301 between the upper chamber portion 101A and the lower chamberportion 101B. The RF gasket 301 is defined to provide a uniformelectrical connection between the upper chamber portion 101A and thelower chamber portion 101B around the entire periphery of the chamber,so as to ensure that a uniform ground potential exists around the entireperiphery of the chamber at the interface between the upper chamberportion 101A and the lower chamber portion 101B. The RF gasket 301 isdefined to provide an amount of flexibility to accommodate variations inthe interface between the upper and lower chamber portions 101A/101B,thereby ensuring full electrical contact between the upper and lowerchamber portions 101A/101B around the periphery of the chamber.

FIG. 4A is an illustration showing a closed version of the chamber 101Chaving an access door 401, in accordance with another embodiment of thepresent invention. The access door 401 is defined to be removed from thechamber 101C to enable access to the interior of the chamber 101C forplacement and retrieval of the of the part 111 and for changing the hotelectrode 109. FIG. 4B is an illustration showing a closed version ofthe chamber 101C with the access door 401 removed, in accordance withanother embodiment of the present invention. In various embodiments, theaccess door 401 can be secured to the chamber 101C in a number of ways,such as through fasteners or clamps. It should be appreciated, however,that regardless of the technique used to secure the access door 401 tothe chamber 101C, the access door 401 should be secured so as toestablish a substantially uniform ground potential between the interfaceof the access door 401 and the chamber 101 c.

In one embodiment, the apparatus 100 is defined to operate at naturalatmospheric and room temperature conditions. However, in anotherembodiment, the apparatus 100 is defined to provide a controlledenvironment within the chamber 101 interior cavity 102 during operationof the apparatus 100. The controlled environment can include acontrolled atmosphere and temperature within the chamber 101 interiorcavity 102. In one embodiment, the atmospheric conditions (such as gascontent, moisture level, pressure, etc.) and temperature within thechamber 101 interior cavity 102 is controlled to substantially emulateatmospheric conditions and temperature to which the part 111 will beexposed during operation of the plasma processing system within whichthe part 111 will be deployed. It should be appreciated that in thisembodiment, a number of gas input and output ports can be disposedwithin the chamber 101 so as to enable supply and removal of various gasmixtures to/from the chamber 101 interior cavity 102. Also, it should beappreciated that in this embodiment a number of support systems can beplumbed to the number of gas input and output ports. These supportsystems can include gas supply systems, pressurization systems, vacuumsystems, gas heating and/or cooling systems, etc., as necessary toestablish the appropriate controlled atmospheric conditions andtemperature with the chamber 101 interior cavity 102.

Determining Capacitance and Dielectric Constant of Part

FIG. 6 is an illustration depicting capacitances between the hotelectrode 109/RF rod 113 and the grounded upper electrode 105/chamber101 when the exemplary part 111 is disposed between the upper electrode105 and the hot electrode 109, in accordance with one embodiment of thepresent invention. As shown in FIG. 6, the capacitance between the upperelectrode 105 and the hot electrode 109 is defined by the capacitance(C_(part)) of the part 111 and the capacitance (C_(st1)) between the hotelectrode 109 and the portions of the upper electrode 105 outside of thecontact region between the part 111 and the upper electrode 105. Also, acapacitance (C_(st2)) exists between the RF rod 113 and the chamber 101bottom. It should be understood that the capacitances (C_(st1)) and(C_(st2)) are functions of the separation distance (Y1) between theupper electrode 105 and the hot electrode 109. Also, the capacitance(C_(part)) is a function of the dielectric constant of the part(k_(part)). Because the capacitances (C_(part)), (C_(st1)), and(C_(st2)) represent parallel capacitances, the total capacitance(C_(total) _(—) _(with) _(—) _(part)) between the hot electrode 109/RFrod 113 and the grounded upper electrode 105/chamber 101 is defined as asum of the capacitances (C_(part)), (C_(st1)), and (C_(st2)), as shownin Equation 1.

(C _(total) _(—) _(with) _(—) _(part))=(C _(part) {k _(part)})+(C _(st1){Y1})+(C _(st2) {Y1})  Equation 1

FIG. 7 is an illustration depicting capacitances between the hotelectrode 109/RF rod 113 and the grounded upper electrode 105/chamber101 when there is no part disposed between the upper electrode 105 andthe hot electrode 109, in accordance with one embodiment of the presentinvention. As shown in FIG. 7, the capacitance between the upperelectrode 105 and the hot electrode 109 is defined by the capacitance(C_(st3)) of the atmosphere within the chamber 101 interior cavity.Also, as in FIG. 6, the capacitance (C_(st2)) exists between the RF rod113 and the chamber 101 bottom. It should be understood that thecapacitances (C_(st3)) and (C_(st2)) in FIG. 7 are functions of theseparation distance (Y2) between the upper electrode 105 and the hotelectrode 109. Because the capacitances (C_(st3)) and (C_(st2))represent parallel capacitances, the total capacitance (C_(total) _(—)_(without) _(—) _(part)) between the hot electrode 109/RF rod 113 andthe grounded upper electrode 105/chamber 101 is defined as a sum of thecapacitances (C_(st3)) and (C_(st2)), as shown in Equation 2.

(C _(total) _(—) _(without) _(—) _(part))=(C _(st3) {Y2})+(C _(st2){Y2})  Equation 2

In the configuration of FIG. 6, with the upper electrode 105 resting ontop of the part 111 positioned in a substantially centered manner on topof the hot electrode 109, the variable capacitor 123 can be adjusted toachieve a particular resonance frequency of the apparatus 100. Becausedielectric properties of the part 111 are frequency dependent, in oneembodiment, the resonance frequency of the apparatus 100 is set to theoperating frequency of the RF power that is to be used in the plasmaprocess to which the part 111 will be exposed when deployed in theplasma processing system. Thus, the apparatus 100 according to theconfiguration of FIG. 6 with the part 111 present in the chamber 101will have a particular resonance frequency.

With reference to the configuration of FIG. 7 with the part absent, itshould be understood that the resonance frequency of the RF power willchange as the distance (Y2) between the upper electrode 105 and the hotelectrode 109 is changed. In the configuration of FIG. 7, the variablecapacitor 123 and RF signal generator 125 are maintained at theirrespective settings as applied in the configuration of FIG. 6 with thepart 111 present in the chamber 101. Under these conditions, the upperelectrode 105 in the configuration of FIG. 7 (without the part present)can be lowered toward the hot electrode 109 until the resonancefrequency of the apparatus 100 according to the configuration of FIG. 7substantially matches the resonance frequency of the apparatus 100according to the configuration of FIG. 6 (with the part 111 present).When the upper electrode 105 is lowered to cause the substantialmatching between the resonance frequencies of the configurations ofFIGS. 6 and 7, the total capacitance (C_(total) _(—) _(with) _(—)_(part)) of configuration 6 will be substantially equivalent to thetotal capacitance (C_(total) _(—) _(with) _(—) _(part)) of configuration7. In this situation, Equations 1 and 2 can be set equal to each otheras shown in Equation 3.

(C _(part) {k _(part)})+(C _(st1) {Y1})+(C _(st2) {Y1})=(C _(total) _(—)_(with) _(—) _(part))  Equation 3

The right side of Equation 3, (C_(total) _(—) _(with) _(—) _(part)) atthe resonance frequency, can be measured directly by connecting acapacitance meter between the RF rod 113 and the upper electrode 105,with the RF rod 113 disconnected from the conductor plate 115 and theupper electrode 105 maintained at the vertical elevation correspondingto the resonance frequency when the part is absent. Also, thecapacitance (C_(st1){Y1}) between the hot electrode 109 and the portionsof the upper electrode 105 outside of the contact region between thepart 111 and the upper electrode 105 in the configuration of FIG. 6 canbe simulated. Also, the capacitance (C_(st2){Y1}) between the RF rod 113and the chamber 101 bottom in the configuration of FIG. 6 can besimulated. In one embodiment, the capacitances (C_(st1){Y1}) and(C_(st2){Y1}) are simulated through a finite element model analysis ofthe configuration of FIG. 6. With the capacitances (C_(total) _(—)_(with) _(—) _(part)), (C_(st1){Y1}), and (C_(st2){Y1}) known, thecapacitance of the part (C_(part){k_(part)}) can be calculated, as shownin Equation 4.

(C _(part) {k _(part)})=(C _(total) _(—) _(with) _(—) _(part))−(C _(st1){Y1})−(C _(st2) {Y1})  Equation 4

Once the capacitance of the part (C_(part){k_(part)}) is calculated, thedielectric constant of the part (k_(part)) can be determined based onthe calculated capacitance of the part (C_(part){k_(part)}). In oneembodiment, the capacitance of the part (C_(part)), as disposed betweenthe upper electrode 105 and the hot electrode 109, is simulated for anumber of different assumed part dielectric constant (k_(part)) values,so as to enable generation of a curve of part capacitance (C_(part))versus part dielectric constant (k_(part)). FIG. 8 is an illustrationshowing an exemplary curve 801 of part capacitance (C_(part)) versuspart dielectric constant (k_(part)). Because the part capacitance(C_(part)) is a linear function of the part dielectric constant(k_(part)), the curve of part capacitance (C_(part)) versus partdielectric constant (k_(part)) will generally be a well-fit line, asillustrated by the curve 801 in FIG. 8. In one embodiment, thesimulation of the part capacitance (C_(part)) for the number ofdifferent assumed part dielectric constant (k_(part)) values isperformed through a finite element model analysis of the part 111disposed between the upper electrode 105 and hot electrode 109. However,in another embodiment, if the geometric configurations of the part 111,the upper electrode 105, and the hot electrode 109 are sufficientlysimple, the part capacitance (C_(part)) for the number of differentassumed part dielectric constant (k_(part)) values may be determinedanalytically. Using the generated curve of part capacitance (C_(part))versus part dielectric constant (k_(part)), and the actual capacitanceof the part (C_(part)) as calculated using Equation 4, the actualdielectric constant of the part (k_(part)) can be determined.

As discussed above, to determine the total capacitance (C_(total) _(—)_(with) _(—) _(part)) at the resonance frequency, it is necessary toknow the relationship between the total capacitance (C_(total) _(—)_(with) _(—) _(part)) and the separation distance between the upperelectrode 105 and the hot electrode 109. FIG. 9 is an illustrationshowing a flowchart of a method for calibrating the relationship betweenthe total capacitance (C_(total) _(—) _(with) _(—) _(part)) and theseparation distance between the upper electrode 105 and the hotelectrode 109, in accordance with one embodiment of the presentinvention. In an operation 901, the RF rod 113 is disconnected from theconductor plate 115 and from any other electrical connection within theelectrical components housing 103. In an operation 903, a capacitancemeter is connected between the RF rod 113 and the upper electrode 105.In an operation 905, using the capacitance meter, the capacitancebetween the RF rod 113 and grounded upper electrode 105 is measured andrecorded for a number of vertical separation distances between the upperelectrode 105 and the hot electrode 109. In one embodiment, operation905 is performed by positioning the upper electrode 105 at a number ofvertical separation distances from the hot electrode 109 extending from0.05 inch to 1.2 inch, in increments of 0.05 inch. In the operation 905,at each vertical separation distance between the upper electrode 105 andthe hot electrode 109, the upper electrode 105 is maintained in asubstantially level horizontal orientation so as to be substantiallyparallel to the hot electrode 109. The method further includes anoperation 907 for generating a capacitance calibration curve for thechamber 101 by plotting the capacitance versus vertical separationdistance between the upper electrode 105 and the hot electrode 109 usingthe data measured in operation 905. The capacitance calibration curvefor the chamber 101 can be repeatedly used to determine the totalcapacitance (C_(total) _(—) _(without) _(—) _(part)) at the resonancefrequency once the vertical elevation of the upper electrode 105 at theresonance frequency (without the part present) is determined.

FIG. 10 is an illustration showing a method for determining acapacitance of a part (C_(part)), in accordance with one embodiment ofthe present invention. The method of FIG. 10 is a representation theprocedure as described above. The method includes an operation 1001 forplacing a part to be measured on the hot electrode 109 within thechamber 101, and for lowering the upper electrode 105 to rest on top ofthe part. In one embodiment, alignment pins are used to enable precisepositioning and alignment of the part on the hot electrode 109. In anoperation 1003, the RF signal generator 125 is operated to transmit RFpower to the hot electrode 109. In an operation 1005, the variablecapacitor 123 is adjusted to achieve the resonance frequency, i.e., peakfrequency, of the RF power. In one embodiment, the resonance frequencycorresponds to a peak gain between the connector 129 and the connector131 of the electrical components housing 103. In this embodiment, the RFvoltmeter 127 can be monitored to identify when the variable capacitor123 setting corresponds to the peak gain between the connectors 129 and131, and thereby corresponds to the resonance frequency of the apparatus100.

The method further includes an operation 1007 for turning off the RFsignal generator 125 and removing the part from the chamber. In anoperation 1009, the RF signal generator 125 is operated to transmit RFpower to the hot electrode 109 with the part absent. In the operation1009, the variable capacitor 123 is maintained at the setting determinedin operation 1005. In an operation 1011, the upper electrode 105 islowered until the resonance frequency determined in operation 1005 isachieved with the part absent. In one embodiment, the RF voltmeter 127can be monitored to identify when the upper electrode 105 elevationcauses the peak gain between the connectors 129 and 131 to be reached,and thereby causes the resonance frequency to be achieved. The verticalseparation distance between the upper electrode 105 and the hotelectrode 109 at the resonance frequency with the part absent is calledthe resonant upper electrode 105 separation.

Once the resonant upper electrode 105 separation is determined, anoperation 1013 is performed to determine the total capacitance(C_(total) _(—) _(with) _(—) _(part)) at the resonance frequency basedon the resonant upper electrode 105 separation. In one embodiment, thecapacitance calibration curve for the chamber 101, as generated in themethod of FIG. 9, is used to determine the total capacitance (C_(total)_(—) _(with) _(—) _(part)) at the resonance frequency in operation 1013.

The method further includes an operation 1015 for simulating both thecapacitance (C_(st1){Y1}) between the hot electrode 109 and the portionsof the upper electrode 105 outside of the contact region between thepart 111 and the upper electrode 105, and the capacitance (C_(st2){Y1})between the RF rod 113 and the chamber 101 bottom. As previouslymentioned, in one embodiment, the capacitances (C_(st1){Y1}) and(C_(st2){Y1}) can be simulated through a finite element model analysis.An operation 1017 is then performed to calculate the capacitance of thepart (C_(part)) as being equal to the total capacitance (C_(total) _(—)_(with) _(—) _(part)) determined in operation 1013 minus thecapacitances (C_(st1){Y1}) and (C_(st2){Y1}) simulated in the operation1015.

FIG. 11 is an illustration showing a flowchart of a method fordetermining the dielectric constant of the part (k_(part)), inaccordance with one embodiment of the present invention. In an operation1101, the capacitance of the part (C_(part)) is simulated and recordedfor a number of assumed part dielectric constant (k_(part)) values. Inan operation 1103, a capacitance versus dielectric constant curve, suchas the example shown in FIG. 8, is generated for the part based on thesimulated data from operation 1101. In an operation 1105, thecapacitance versus dielectric constant curve of operation 1103 is usedto determine the dielectric constant of the part (k_(part)) thatcorresponds to the capacitance of the part (C_(part)) as determined inthe method of FIG. 10.

Determining Loss Tangent of Part

FIG. 12 is an illustration showing a flowchart of a method fordetermining a loss tangent of a part, in accordance with one embodimentof the present invention. The method includes an operation 1201 forplacing a part to be measured on the hot electrode 109 within thechamber 101, and for lowering the upper electrode 105 to rest on top ofthe part. In an operation 1203, the RF signal generator 125 is operatedto transmit RF power to the hot electrode 109. In an operation 1205, thevariable capacitor 123 is adjusted to achieve the resonance frequency,i.e., peak frequency, of the RF power. In one embodiment, the resonancefrequency corresponds to a peak gain between the connectors 129 and 131of the electrical components housing 103. In this embodiment, the RFvoltmeter 127 can be monitored to identify when the variable capacitor123 setting corresponds to the peak gain between the connectors 129 and131, and thereby corresponds to the resonance frequency of the apparatus100.

The method continues with an operation 1207 in which the RF signalgenerator 125 is controlled to sweep the frequency of the RF power overa range bounding the resonance frequency achieved in operation 1205,while using the RF voltmeter 127 to measure and record the gain of theapparatus 100 between the connections 129 and 131 at a number offrequencies within the frequency sweep range. In one embodiment, thefrequency range covered by the frequency sweep of operation 1207 isdefined to include a 3 dB variation in gain of the apparatus 100 on eachside of the peak gain corresponding to the resonance frequency. Themethod further includes an operation 1209 for fitting a mathematicalmodel of the gain of the apparatus 100 to the gain versus frequency datameasured in operation 1207, wherein the fitting of operation 1209provides a value for the total capacitance of the apparatus 100 with thepart therein (C_(total) _(—) _(with) _(—) _(part)) and a value for thetotal resistance of the apparatus 100 with the part therein (R_(total)_(—) _(with) _(—) _(part)). The fitting of operation 1209 is furtherdescribed below with regard to FIGS. 13-14 and Equation 5.

FIG. 13 is an illustration showing an equivalent electrical circuitrepresentation 1300 of the apparatus 100 with the part 111 disposedbetween the upper electrode 105 and hot electrode 109, as depicted inFIG. 1, in accordance with one embodiment of the present invention. Anode 1313 corresponds to the connector 129 of the electrical componentshousing 103. A node 1315 corresponds to the connector 131 of theelectrical components housing 103. The RF voltmeter 127 connected toconnectors 129 and 131 is capable of measuring a gain of the apparatus100 as defined by |V_(out)/V_(in)|. With regard to FIG. 1, theequivalent electrical circuit 1300 includes a capacitance (C_(S)) 1301representing the capacitor 117, an inductance (L) 1303 and resistance(R_(L)) 1305 representing the inductor 119, a capacitance (C) 1307representing the total capacitance of the apparatus 100, a resistance(R_(X)) 1309 representing the total resistance of the apparatus 100, anda ground potential 1311. It should be understood that the capacitance(C) 1307 represents the combination of the capacitors 121 and 123, thecapacitance between the RF rod 113/hot electrode 109 and chamber101/upper electrode 105, and the capacitance of the part 111 if present.

Equation 5 defines the gain of the apparatus 100 as a function of theelectrical components within the equivalent electrical circuit 1300 ofFIG. 13. In Equation 5, (f) is the frequency of the RF powercorresponding to the gain, (C) is the total capacitance of the apparatus100, and (R_(X)) is the total resistance of the apparatus 100. InEquation 5, the parameters (C_(S)), (L), (R_(L)) are known from theelectrical components in the electrical components housing 103.Therefore, in Equation 5, the parameters (C) and (R_(X)) represent theunknown parameters.

$\begin{matrix}{{Gain} = {\frac{1}{\begin{matrix}\left( {{- \frac{}{2C_{s}f\; \pi}} + \frac{1}{{2\; {Cf}\; \pi} + \frac{1}{{2f\; {\pi}\; L} + R_{L}} + \frac{1}{R_{X}}}} \right) \\\left( {{2\; {Cf}\; \pi} + \frac{1}{{2f\; \; \pi \; L} + R_{L}} + \frac{1}{R_{X}}} \right)\end{matrix}}}} & {{Equation}\mspace{14mu} 5}\end{matrix}$

In the operation 1209, Equation 5 is fit to the gain versus frequencydata measured in operation 1207 with the part present in the apparatus100, thereby yielding a value for the total capacitance of the apparatus100 with the part therein, i.e., (C)=(C_(total) _(—) _(with) _(—)_(part)) and a value for the total resistance of the apparatus 100 withthe part therein, i.e., (R_(X))=(R_(total) _(—) _(with) _(—) _(part)).FIG. 14 is an illustration showing an exemplary fitting of Equation 5 inaccordance with operation 1209, based on gain versus frequency datameasured and recorded in the frequency sweep of operation 1207. In oneembodiment, a multivariate regression technique is used to fit Equation5 to the measured gain versus frequency data in operation 1209. Also, inone embodiment, a confidence interval for each of the unknown parameters(C) and (R_(X)) is estimated by Monte Carlo simulation.

The method of FIG. 12 continues with an operation 1211 for turning offthe RF signal generator 125 and removing the part from the chamber. Inan operation 1213, the RF signal generator 125 is operated to transmitRF power to the hot electrode 109 with the part absent. In the operation1213, the variable capacitor 123 is maintained at the setting determinedin operation 1205. In an operation 1215, the upper electrode 105 islowered until the resonance frequency determined in operation 1205 isachieved with the part absent. In one embodiment, the RF voltmeter 127can be monitored to identify when the upper electrode 105 elevationcauses the peak gain between the connectors 129 and 131 to be reached,and thereby causes the resonance frequency to be achieved. As previouslymentioned, the vertical separation distance between the upper electrode105 and the hot electrode 109 at the resonance frequency with the partabsent is called the resonant upper electrode 105 separation.

The method continues with an operation 1217 in which the RF signalgenerator 125 is controlled to sweep the frequency of the RF power overa range bounding the resonance frequency achieved in operation 1215,while using the RF voltmeter 127 to measure and record the gain of theapparatus 100 between the connections 129 and 131 at a number offrequencies within the frequency sweep range. In one embodiment, thefrequency range covered by the frequency sweep of operation 1217 isdefined to include a 3 dB variation in gain of the apparatus 100 on eachside of the peak gain corresponding to the resonance frequency. Themethod further includes an operation 1219 for fitting a mathematicalmodel of the gain of the apparatus 100, i.e., Equation 5, to the gainversus frequency data measured in operation 1217. The fitting ofoperation 1219 provides a value for the total capacitance of theapparatus 100 with the part absent, i.e., (C)=(C_(total) _(—) _(with)_(—) _(part)), and a value for the total resistance of the apparatus 100with the part absent (R_(X))=(R_(total) _(—) _(without) _(—) _(part)).As previously mentioned, a multivariate regression technique can be usedto fit Equation 5 to the measured gain versus frequency data inoperation 1219. Also, in one embodiment, a confidence interval for eachof the unknown parameters (C) and (R_(X)) is estimated by Monte Carlosimulation.

The method continues with an operation 1221 for calculating theresistance of the part (R_(part)) based on the total resistance of theapparatus 100 with the part therein (R_(total) _(—) _(with) _(—)_(part)), as determined in operation 1209, and the total resistance ofthe apparatus 100 with the part absent (R_(total) _(—) _(without) _(—)_(part)), as determined in operation 1219. More specifically, theresistance of the part (R_(part)) is determined using Equation 6.

$\begin{matrix}{\frac{1}{R_{part}} = {\left. {\frac{1}{R_{{total\_ without}{\_ part}}} - \frac{1}{R_{{total\_ with}{\_ part}}}}\Rightarrow R_{part} \right. = \frac{\left( R_{{total\_ with}{\_ part}} \right)\left( R_{{total\_ without}{\_ part}} \right)}{R_{{total\_ with}{\_ part}} - R_{{total\_ without}{\_ part}}}}} & {{Equation}\mspace{14mu} 6}\end{matrix}$

The method then includes an operation 1223 for calculating the losstangent of the part based on the resistance of the part (R_(part)), asdetermined in operation 1221, the capacitance of the part (C_(part)), asdetermined in the method of FIG. 10, and the resonance frequency, i.e.,peak frequency, corresponding to operations 1205 and 1215. Morespecifically, the loss tangent of the part is determined using Equation7.

$\begin{matrix}{{{Loss}\mspace{14mu} {Tangent}\mspace{14mu} {of}\mspace{14mu} {Part}} = \frac{1}{\left( {{Resonance}\mspace{14mu} {Frequency}} \right)\left( R_{part} \right)\left( C_{part} \right)}} & {{Equation}\mspace{14mu} 7}\end{matrix}$

Based on the foregoing, it should be appreciated that the apparatus 100and the associated methods (FIGS. 5B, 9, 10, 11, and 12) provide formeasurement of the dielectric properties of actual full-size parts to bedeployed in a plasma processing system. Also, the apparatus 100 andassociated methods provide for measurement of the dielectric propertiesof parts at the actual operating frequency of the RF power to which thepart will be exposed during plasma processing operations. Furthermore,the apparatus 100 and associated methods provide for measurement of thedielectric properties of parts under simulated atmospheric conditionsand temperatures to which the part will be exposed during plasmaprocessing operations. Additionally, the apparatus 100 and associatedmethods have been demonstrated to provide a loss tangent measurementrepeatability having standard deviation of less than 1.24E-5.

In one embodiment, the dielectric properties of the full-size partdetermined through use of the apparatus 100, such as the dielectricconstant value and the loss tangent value, can be attached to thefull-size part. In one embodiment, the determined dielectric constantand loss tangent values are embossed on the full-size part. For example,FIG. 5A shows an example of dielectric constant and loss tangent valuesembossed on the part 111A. In another embodiment, a tag is affixed tothe full-size part to display the determined dielectric constant andloss tangent values. Additionally, the determined dielectric constantand loss tangent values of the full-size part can be stored on acomputer readable medium, which can be supplied in conjunction with thefull-size part.

With the above embodiments in mind, it should be understood that theinvention can employ various computer-implemented operations involvingdata stored in computer systems. These operations are those requiringphysical manipulation of physical quantities. Usually, though notnecessarily, these quantities take the form of electrical or magneticsignals capable of being stored, transferred, combined, compared andotherwise manipulated. Further, the manipulations performed are oftenreferred to in terms such as producing, identifying, determining, orcomparing. Any of the operations described herein may be directed,controlled, or performed by a computer system. The computer system canbe specially constructed for the required purpose, or the computersystem can be a general-purpose computer selectively activated orconfigured by a computer program stored in the computer.

A computer program can be defined to control and monitor the apparatus100 and perform the calculations associated with measuring thedielectric properties of a part utilizing the apparatus 100. Such acomputer program can be defined to provide a graphical user interface(GUI) for enabling a user to control the apparatus 100, monitor a stateof the apparatus 100, view data acquired by the apparatus 100, controlcalculations based on the data acquired by the apparatus 100, and viewand record data/results generated through operation of the apparatus100. Such a computer program can be embodied as computer readable codeon a computer readable medium. The computer readable medium is any datastorage device that can store data, which can be thereafter be read by acomputer system. Examples of the computer readable medium include harddrives, network attached storage (NAS), read-only memory, random-accessmemory, CD-ROMs, CD-Rs, CD-RWs, magnetic tapes and other optical andnon-optical data storage devices.

While this invention has been described in terms of several embodiments,it will be appreciated that those skilled in the art upon reading thepreceding specifications and studying the drawings will realize variousalterations, additions, permutations and equivalents thereof. Therefore,it is intended that the present invention includes all such alterations,additions, permutations, and equivalents as fall within the true spiritand scope of the invention.

1. An electrode for use in measuring dielectric properties of a part,comprising: a plate formed from an electrically conductive material, theplate having a top surface defined to support a part to be measured, theplate having a bottom surface defined to be connected to aradiofrequency (RF) transmission rod such that RF power can betransmitted through the RF transmission rod to the plate, wherein theplate is defined to have a number of holes cut vertically through theplate at a corresponding number of locations that underlie embeddedconductive material items in the part to be measured when the part ispositioned on the top surface of the plate.
 2. An electrode for use inmeasuring dielectric properties of a part as recited in claim 1, whereinthe plate is formed from copper metal.
 3. An electrode for use inmeasuring dielectric properties of a part as recited in claim 1, whereina vertical thickness of the plate from the top surface to the bottomsurface is within a range extending from about 0.125 inch to about 2inches.
 4. An electrode for use in measuring dielectric properties of apart as recited in claim 1, wherein a vertical thickness of the platefrom the top surface to the bottom surface is about 0.75 inch.
 5. Anelectrode for use in measuring dielectric properties of a part asrecited in claim 1, wherein the plate includes a number of alignmentfeatures defined to facilitate alignment of the part to be measured onthe top surface of the plate.
 6. An electrode for use in measuringdielectric properties of a part as recited in claim 1, wherein aperiphery of the plate is defined to be proximate to a periphery of thepart to be measured when the part to be measured is positioned on thetop surface of the plate so as to be substantially centered on the topsurface of the plate.
 7. An electrode for use in measuring dielectricproperties of a part as recited in claim 1, wherein the plate is definedto be an interchangeable component within an apparatus for measuringdielectric properties of the part.
 8. A method for defining an electrodefor use in measuring dielectric properties of a part, comprising:forming a plate of electrically conductive material to have an outerperimeter defined to substantially match an outer perimeter of a part,wherein the part is a dielectric part including a number of embeddedconductive material items; identifying a location of each embeddedconductive material item within the part; projecting the identifiedlocation of each embedded conductive material item within the part uponthe plate with the outer perimeters of the part and the platesubstantially aligned; and removing a portion of the plate at eachembedded conductive material item location as projected upon the plate.9. A method for defining an electrode for use in measuring dielectricproperties of a part as recited in claim 8, wherein a size of eachremoved portion of the plate is sufficient to ensure that the plate isnot located below the embedded conductive material item within the partwhen the part is positioned upon the plate with the outer perimeters ofthe part and the plate substantially aligned.
 10. A method for definingan electrode for use in measuring dielectric properties of a part asrecited in claim 8, wherein removing the portion of the plate at eachembedded conductive material item location is performed such that theplate remains a single contiguous component.
 11. A method for definingan electrode for use in measuring dielectric properties of a part asrecited in claim 8, wherein the plate is formed from copper metal.
 12. Amethod for defining an electrode for use in measuring dielectricproperties of a part as recited in claim 8, wherein a vertical thicknessof the plate from a top surface of the plate to a bottom surface of theplate is within a range extending from about 0.125 inch to about 2inches.
 13. A method for defining an electrode for use in measuringdielectric properties of a part as recited in claim 8, furthercomprising: forming a number of alignment features within the plate tofacilitate alignment of the part on a top surface of the plate.
 14. Amethod for defining an electrode for use in measuring dielectricproperties of a part as recited in claim 8, further comprising: forminga number of fastening devices within the plate to enable securing of theplate to a support rod within an apparatus for measuring dielectricproperties of the part.
 15. An electrode for use in measuring dielectricproperties of a ring-shaped part, wherein the ring-shaped part includesa number of embedded conductive material items circumferentiallydisposed within the ring-shaped part, comprising: a plate formed from anelectrically conductive material, wherein the plate includes a solidcenter region and a number of spokes extending radially outward from thesolid center region by an extent sufficient to enable support of thering-shaped part on a top surface of each of the number of spokes,wherein the number of spokes are defined and spaced about the solidcenter region such that the number of spokes support the ring-shapedpart at locations between adjacent embedded conductive material itemswithin the ring-shaped part.
 16. An electrode as recited in claim 15,wherein the solid center region and each of the number of spokes aredefined to have a substantially uniform vertical thickness extendingfrom a top surface of the plate to a bottom surface of the plate.
 17. Anelectrode as recited in claim 16, wherein the substantially uniformvertical thickness is about 0.75 inch.
 18. An electrode as recited inclaim 15, wherein the plate is formed from copper metal.
 19. Anelectrode as recited in claim 15, wherein adjacent ones of the number ofspokes are separated from each other by a gap within which the plate isabsent.
 20. An electrode as recited in claim 15, wherein a bottomsurface of the solid center region of the plate includes a number offastening devices defined to enable securing of the plate to a supportrod within an apparatus for measuring dielectric properties of the part.